With the advance of semiconductor industries and the requirements of users recently, electronic devices are being more highly integrated and have high performances, and thus semiconductor devices that are the main components of the electronic devices are also required to be highly integrated and have high performance. However, it is difficult to realize a fine structure for highly integrating semiconductor devices.
For example, a thinner insulating film is required for realizing the fine structure, but if the insulating film is formed to a thin thickness, film properties such an insulation characteristic are degraded. Also, it is becoming more difficult to form a thin film with a thin thickness while obtaining excellent step coverage.